The power needed to run servers and other components in a server rack system is provided by power supply units. As the number of servers (e.g., nodes) in the rack increases, the electricity required to power the servers increase. As the power requirements of the servers increase, more power supply units are needed to supply the power requirements of the servers. Typically, a rack is configured with a number of power supply units necessary to satisfy the peak power requirements of the servers in the rack. Sometimes additional power supply units beyond the minimum necessary number will be included in the rack system to handle power supply unit failures (e.g., provide a redundant power supply unit). By providing excess power capacity (e.g., beyond the minimum required for the rack system), the servers in the rack can continue to operate even if one of the power supply units fails. However, running, for example, six (6) power supply units in a rack, when only four (4) are required wastes energy and unnecessarily wears out the extra power supply units.